Method and apparatus for bulking yarn

ABSTRACT

An apparatus utilizing ultrasonic components was designed and used in combination with select chemicals to produce permanent bulking in cotton and other yarns. The method constitutes immersing the yarns in cross-linking formulations and subjecting these while immersed to ultrasonic irradiation. An extension of the method comprises imparting resiliency to the bulked yarns. This is accomplished both by mechanical and by chemical means.

Unite States atent {151 3,646,744 Rusca Mar. 7, 1972 [54] METHOD ANDAPPARATUS FOR 2,943,377 7/1960 Freiberger ..28/72.1 X BULKING YARN2,946,181 7/1960 Tissot et al..., ..57/l57 2,956,393 10/1960 Ubbelohde..57/l57 [721 Ralph New Orleans 3,211,159 10/1965 Goble ..28/72.1 x [73]Assignee: The United States 0i America as 3,304,593 2/1967 -l Xrepresented by the Secretary of Agricul- 3,438,104 4/ 1969 Stoller..28/72.1 ture Primary Examiner--Donald E. Watkins l d. 2 69 [22] 8 Dec2 19 Att0meyR. Hoffman and W. Bier [21] Appl. No.: 886,861

[57] ABSTRACT [52] U.S.Cl ..57/34 B, 28/1 R,57/34 HS, An apparatusutilizing ultrasonic components was designed 57/ 157 T5 and used incombination with select chemicals to produce perg "D023 gf fi g fs ts ig manent bulking in cotton and other yarns. The method conla 0 arestitutes immersing the yarns in cross-linking formulations and 57/157157 157 F; 28/721 1 subjecting these while immersed to ultrasonicirradiation. An extension of the method comprises imparting resiliencyto the [56] References and bulked yarns. This is accomplished both bymechanical and by UNITED STATES PATENTS chemical means- 2,815,55912/1957 Robinson ..57/34 UX 4 Claims, 3 Drawing Figures PATENTEDHAR H912,7

SHEET 1 033 FIG.I

INVENTOR RALPH A. RusqA ATTORNEY PATENTEUHAR 7 I972 SHEET 2 [1F 3 FIGZINVENTOR RALPH A. RUSCA ATTORNEY PATENTED MAR 7 I972 SHEET 3 UF 3 IINVENTOR RALPH A. RUSCA METHOD AND APPARATUS FOR BULKING YARN Anonexclusive, irrevocable, royalty-free license in the invention hereindescribed, throughout the world for all purposes of the United StatesGovernment, with the power to grant sublicenses for such purposes, ishereby granted to the Government of the United-States of America.

This invention relates to an apparatus and a method for bulking yarns.Specifically, this invention relates to the use of combined chemical andphysical means to cause and retain a bulked configuration of yarns. Morespecifically, this invention relates to imparting to cellulosic andnoncellulosic yarns a permanent bulked configuration simply by applyingultrasonic irradiation to a bath solution which contains the yarns beingtreated in a cross-linking chemical formulation. The yarns thus bulkedcan be used in a great variety of fabrics which go into the home eitheras articles of wear or as bedspreads, towels, draperies, and many othersuch.

It is well known to those skilled in the art of bulking or texturizingtextile yarns that yarns produced from manmade staple fibers can bebulked by a variety of processes and apparatuses, and that yarnsproduced from natural fiber cannot be bulked successfully. Yarns madefrom cotton fibers particularly, have not been responsive toconventional bulking methods of the prior art. Prior to the disclosureof the instant invention four general methods have been used for bulkingyams. These are (l) the application of air jets, (2) use of a stufferbox or similar crimping techniques, (3) drawing the yarn over a sharpedge, and (4) falsetwisting. Following the bulking process the yarns arefixed in the bulked condition by the application of heat that causesplastic flow (in some fibers) and permanently sets the yarn. Efforts toproduce bulked yarns of natural fibers by these methods have failedbecause natural fibers do not have the plastic flow or heat settingproperties of manmade fibers.

The main object of the present invention is to provide bulked textileyarns produced by a unique and novel method.

A second object of the instant invention is to provide the apparatus touse with the method for producing the new bulked yarns.

These objects are accomplished by utilizing acoustic energy in a liquidmedium to bulk the yarns, the liquid medium being a resin treatingformulation to set the bulked configuration permanently upon curing.

A further object of the invention is to produce bulked yarns havingstretch properties by falsetwisting the bulked, resintreated yarn andpermanently setting the yarn in this state.

While the invention herein disclosed utilizes description applicable toyarns made from cotton fibers this should not be misconstrued to implyrestriction to cotton yarns. The instant invention can be used withcotton and other cellulosic yarns, with noncellulosic yarns, and it canalso be used with blends. The yarns can be mixed staple fiber ormonofilamentous.

To restate the description of the instant invention, one facet of theinvention is the apparatus consisting of a select combination ofcomponents comprising mainly an acoustic energy generator, a transducerunit for applying the acoustic energy to the yarn, a means for treatingthe yarn with suitable resins, a means for drying and curing the treatedyarns, a yarn supply device (for holding a feed package), a yarn takeupdevice (for receiving a treated package quantity), and associated meansfor driving the component rotating parts.

Another facet of the invention is the method of using the apparatus ofthe invention. The method generally consists of subjecting the yarns toacoustic energy irradiation while the yarns are immersed in a selectcross-linking formulation, then drying and curing the bulked,impregnated yarns to impart to these a permanent configuration.

Projections of the instant invention include the production and methodof producing bulked yarns with stretch properties, or with resistance toweather, biological degradation, flame, or physical deformation. Theseobjectives are accomplished by chemical means, physical means, or acombination thereof. Falsetwisting is one way of accomplishing thephysical means of adding stretch to the bulked yarns. Chemically,stretch may be added to the bulked yarns by treating the bulked yarnwith a chemical agent selected from known swelling agents, such assodium hydroxide, zinc chloride, ethylene diamine, and the like, butbearing in mind that the swelling agent selected must be inert to thecross-linking agent employed in the bath of the earlier process.

Another manner of introducing stretch to a bulked yarn is by achemical-physical combination treatment which can be made to follow andcontinuous with the bulking process. This is explained later. This andother specific supplementary properties can be imparted to a bulked yarnby supplementary treatments with known formulations employed during orafter bulking.

Other objects and advantages of the instant invention will becomeapparent during the following discussion of the drawings.

FIG. 1 is a chematic elevation view of the apparatus for bulking yarns,showing the yarn input and output packages, acoustic treating means,resin bath, drying and curing means, and driving means.

FIG. 2 is a schematic elevation view adding to the components of FIG. 1a falsetwisting means in order to add stretch to the finished, bulkedyarn physically.

FIG. 3 is a schematic elevation view adding to the components of FIG. 1a second chemical bath in order to add stretch to the finished, bulkedyarn chemically.

Referring now to the drawings, FIG. 1 is an embodiment showing anacoustic generator 10, capable of, for example, 10 to 100 watts poweroutput at 60 hertz/second to l megahertz/second frequency, connected byleads 11, to a ceramic-type transducer 12, which is hermetically sealedin tank 13. Other methods of generating acoustic energy may be used,such as magnetostrictive or barium titanate transducers coupled to anelectronic variable or fixed frequency oscillator, or an acoustic horn.The transducers may have a flat surface, or may have a curved surfacedesigned to focus the energy on the yarn. Obviously, either type surfacemay be large enough to enable processing multiple yarns, or evenfabrics.

Tank 13 represents a vessel to contain a cross-linking agent, such as a5 to 20 percent dimethylol ethyleneurea, and is maintained at relativelyconstant temperature and volume by conventional means, not shown. Undersome conditions, however, it may be preferable to put the solution undervacuum or under pressure, or to heat or cool the solution to expeditetreating the yarns. The yarn 15 from package 16 is pulled over rotatableguide roll 17 mounted on bearings, not shown, by coacting rolls l8, 18'mounted on bearings, not shown. Preferably, rolls l8, 18' are positivelydriven by V-belt 19 from DC electric motor 20 whose rotational speed iscontrolled by rheostat 21. Rolls l8, 18 can also serve as squeeze rollsto remove excess liquid from the yarn.

During passage of the yarn through the liquid bath, the action of theacoustic transducer imparts bulk to the yarn. The exact reason for thisphenomenon is not known, but it is believed that the acoustic energycauses vaporous cavitation which puts tremendous pressures on the yarnand this in turn results in an increase in crimp, curl, and matting ofthe individual fibers. The fibers contract and tend to separate fromeach other, resulting in increased bulk and diameter of the yarn. Thisbulking phenomenon can be achieved by a wide range of frequencies andintensities of acoustic energy. For example, it has been determined that20 to 800 kHz. frequency at l to 10 watts/cm will cause vaporouscavitation with associated powerful shock waves that will bulk single ormultiple yarns. A 3-inch diameter ceramic transducer at 800 kHz. and 10watts/cm. will concentrate about percent of its energy in a solid coneof 6 apex angle around its main axis. Yarn or yarns passed through thisenergy zone will bulk rapidly.

Returning to FIG. 1, rolls 18, 18' pull the yarn 15 from supply package16 with a minimum of tension so that the yarn can contract at will underthe influence of the acoustic energy. The acoustic energy also serves tothoroughly impregnate the yarn and fibers with the resin formulation.The treated yarn passes through a conventional hot air or steam heateddrier 22 wherein the resin treated bulked yarn is dried and the resin iscured. This curing of the resin permanently sets the bulked yarn so thatit can be woven, knitted, and otherwise handled without losing itsbulked properties. The bulked yarn is wound on a rotatable package 23mounted on bearings, not shown, by a conventional friction roll 24driven by belt 25 from motor 20. Bearings for this roll are now shown.This form of friction takeup eliminates the need for synchronizingpackage 23 with rolls 18, 18''. However, other driving methods can beused. In fact, coacting rolls 18,18 need not be positively driven, inwhich case friction drive 24 can be replaced by a positive drive system.

Other modifications of the apparatus of the invention will be obvious tothose skilled in the art. A tensioning device can be applied to the yarnbetween supply package 16 and rolls 18, 18' so that constant tension isexerted on to yarn regardless of type of yarn or apparatus speed.Dielectric heating as a means of drying and curing the yarn can besubstituted for drier 22. In fact, drying and curing resin treated yarnhas been successfully carried out using a 1 kw., 8.0 MHz. radiofrequencygenerator in combination with the electrodes disclosed in US. Pat. No.2,492,187. A superior product is produced, but the dielectric drier isexpensive.

In addition to providing the resin formulation for permanently fixingthe bulked yarn, tank 13 can contain other chemicals to impart otherdesirable properties. For example, bath 14 can be formulated to containdimethylol ethyleneurea for bulking, carboxymethyl cellulose forantisoiling, copper naphthanate for mildewproofing,tetrakis(hydroxymethyl)phosphonium chloride for flame resistance, andany dye that is compatible with the resin formulations and the fiber.Other possibilities for multipurpose treatments will be obvious to thoseskilled in the art of textile finishing.

Under proper conditions, the liquid bath method of treatment can bereplaced by a method of applying the resins in vapor phase. Under thiscondition the efficiency of transfer of acoustic energy -to the yarn isreduced somewhat, and processing speeds tend to be lowered.

While the invention has been discussed in terms of yarn bulking, it isalso feasible to bulk fabrics. The degree of bulking will not be asgreat as with yarns, but a substantial increase in fabric bulk can beachieved.

FIG. 2 discloses an embodiment of the invention whereby a bulked yarnwith stretch properties is produced. Referring to FIG. 2, yarn 30 withtwo or more plies from supply package 31 is passed through resintreating bath 14. The yarn is subjected to acoustic energy by transducer12 which is coupled to acoustic generator 10 by leads 11. Roll 70 guidesthe yarn into bath 14. Roll 70 is a device that puts constant tension onthe yarn as it is pulled forward by windup package 37. Package 37 isdriven by a conventional friction drive 24 which is connected by V-belt25 to DC electric motor 20. The motor is controlled by a standardrheostat 21 in line with a source of DC power, not shown. Drier 22 is aconventional hot air or steam drier.

In operation, the yarn is bulked and resin impregnated as heretoforedescribed in connection with FIG. 1. Before the yarn is dried and cured,however,it is falsetwisted by a conventional falsetwister head 43 whichimparts a high degree of falsetwist to the yarn between tension device70 and package 37. The yarn is dried and set while in this twistedconfiguration. The result is a bulked yarn capable of 100 percent ormore stretch from the relaxed state. The degree of stretch is determinedby the number of turns of falsetwist in the yarn; this can be varied atwill be changing the relationship of the rotational speed of thefalsetwister and the delivery rate of the yarn. The treated yarn iswound into a conventional package.

As a practical example, /2 yarn made with 12 turns per inch of S" plytwist is treated with 20 kHz., 10 watts/cm. acoustic energy in a bath ofdimethylol ethyleneurea crosslinking resin. The yarn is falsetwistedwith 40 turns per inch in the 2" twist direction. The falsetwisted yarnis dried and cured and wound on a package.

In some instances it has been found advantageous to make roll a freelyrotating tensionless roll and to make roll 44 a tension control device.This procedure reduces the length of yarn being falsetwisted and therebyimproves the uniformity of stretch properties. On the other hand, afalsetwist inserted in the longer length of yarn between roll 70 andpackage 37 results in wringing out more moisture from the yarn and thusallows an increase in processing speed in those cases where processingspeed is handicapped by lack of drying capacity.

Low-twist yarns have been found to bulk more rapidly and to a largerdegree than high-twist yarns.

Another embodiment for producingbulked, stretch yarns is disclosed inFIG. 3. This embodiment is essentially a two-stage continuous yarnsystem. Yarn 50 from package 51 is pulled through resin bath 14 whereinthe yarn is bulked by acoustic irradiation from transducer 12 coupled byleads 11 to acoustic generator 10. After bulking and resin treatment,yarn 50 is dried and cured in hot air drier 56. The yarn is pulledthrough drier 56 by rolls 57, 57 which are positively driven by anyconventional means (not shown), and the said yarn thereafter passedthrough a bath 58 containing an appropriate catalyst to break a numberof cross-links between the resin and the fiber. The yarn is falsetwistedby a conventional falsetwisting head 43, and is dried and cured in hotair drier 60. Those cross-links which were broken by catalyst in thebath are reformed in the falsetwisted position and are cured in thisposition, thereby imparting permanent stretch to the yarn. The yarn iswound onto package 61 by friction drive 24, which is driven by DCelectric motor 20 through V-belt 25. Motor 20 is controlled by arheostat 21 to provide any desired speed. Any conventional source of DCpower may be used, and is not shown.

The use of a friction drive on takeup package 61 obviates the need forsynchronizing the yarn takeup with the yarn input or with any other partof the system. If desired, however, any of the well-known synchronousdrive systems can be used to control speeds throughout the apparatus.

Restating the embodiment of the invention represented by FIG. 3, achemical-physical step is added to the idea of bulking with ultrasonicirradiation while the yarn is submerged in a cross-linking formulation.The chemical-physical step consists of l) reimmersing the yarn, thistime in a solution containing a catalyst generally used in resin curing,such as, for example, a 2 percent solution of magnesium chloride or zincnitrate, or a mixed catalyst solution containing about 0.5 percent eachof magnesium chloride and citric acid, thereby breaking some of thecross-links established earlier, (2) falsetwisting the wet yarn, and (3)while the yarn is being moved with a minimum of tension to therepackaging step, heat curing the yarn again to reestablish thecross-links in a twisted configuration thereby producing a bulked yarnwith stretch properties.

I claim:

1. A method of imparting a stretchable bulked configuration tocellulosic and other textile yarns which comprises:

a. immersing a textile yarn in a solution containing a crosslinkingagent;

b. subjecting the yarn, while so immersed, to acoustic energyirradiation to cause said yarn to acquire a bulked configuration;

c. transporting the wet bulked yarn with a minimum of tension to aheating zone;

d. applying a falsetwist to the yarn while being transported and beforesaid yarn reaches the curing zone; and

e. heating the falsetwisted yarn to cure the cross-linking agent therebyproducing a cross-linked stretchable, bulked yarn.

2. A method of imparting a stretchable bulked configuration tocellulosic and other textile yarns which comprises:

a. immersing a textile yarn in a solution containing a crosslinkingagent;

b. subjecting the yarn, while so immersed, to acoustic energyirradiation to cause said yarn to acquire a bulked configuration;

c. heating the wet bulked yarn, while under a minimum of tension, tocure the cross-linking agent, thereby crosslinking the yarn and settingthe bulked configuration;

d. passing said cross-linked yarn through a catalyst solution topartially break the cross-links while applying a falsetwist to the wetyarn; and

e. then heating the wet, falsetwisted yarn to recure the cross-linkingagent to set the falsetwist, thereby producing a cross-linkedstretchable bulked yarn.

3. Apparatus for imparting a stretchable, bulked c0nfiguration tocellulosic and other textile yarns comprising:

a. a source of supply of said yarn;

b. a tank for containing a solution of chemical cross-linking agent toreact with the yarn, said tank having a yarn inlet point and a yarn exitpoint;

c. transducer means mounted within said tank;

(1. means for generating an electrical signal having at least a sonicfrequency connected to said transducer;

e. heating means disposed outside and beyond the yarn exit point of thetank;

f. transporting means for passing yarn from the source of supply inproximity to the transducer and then through the heating means, saidtransporting means including first guide means for guiding yarn fromsaid source of supply to the entrance point of the tank, second guidemeans to maintain yam immersed in the tank in proximity to thetransducer, first driven means for withdrawing yarn through the exitpoint of the tank while applying a minimum of tension to the yearn, andsecond driven means beyond the heating means for drawing yarn from thefirst driven means through said heating means; and

g. means disposed between said first and second driven means forapplying a falsetwist to the yarn prior to its passage into the heatingmeans.

4. Apparatus for imparting a stretchable, bulked configuration tocellulosic and other textile yarns comprising:

a. a source of supply of said yarn;

b. a first tank for containing a solution of a chemical crosslinkingagent to react with the yarn;

c. transducer means mounted within said first tank;

d. means for generating an electrical signal having at least a sonicfrequency connected to said transducer;

e. a second tank for containing a cross-link breaking catalyst solution;

f. first heating means located between said first and second tanks;

g. driven windup means for winding up finished, treated h. yarntransporting means for passing yarn, serially, from the source of supplythrough the first tank, the first heating means, through the secondtank, and finally to said windup means, said transporting meansincluding means for guiding yarn into and out of said first tank whilepassing said yarn in proximity to the transducer, means for guiding saidyarn from the first tank through the first heating means to the secondtank, and means for guiding said yarn from said second tank to the yarnwindup means;

i. means for driving said windup means while applying a minimum oftension to the yarn;

j. second heating means disposed between the second tank and windupmeans for heating yarn withdrawn from said second tank; and

k. means disposed between the windup means and the second tank forapplying a falsetwist to the yarn prior to its passage through thesecond heating means.

1. A method of imparting a stretchable bulked configuration tocellulosic and other textile yarns which comprises: a. immersing atextile yarn in a solution containing a crosslinking agent; b.subjecting the yarn, while so immersed, to acoustic energy irradiationto cause said yarn to acquire a bulked configuration; c. transportingthe wet bulked yarn with a minimum of tension to a heating zone; d.applying a falsetwist to the yarn while being transported and beforesaid yarn reaches the curing zone; and e. heating the falsetwisted yarnto cure the cross-linking agent thereby producing a cross-linkedstretchable, bulked yarn.
 2. A method of imparting a stretchable bulkedconfiguration to cellulosic and other textile yarns which comprises: a.immersing a textile yarn in a solution containing a cross-linking agent;b. subjecting the yarn, while so immersed, to acoustic energyirradiation to cause said yarn to acquire a bulked configuration; c.heating the wet bulked yarn, while under a minimum of tension, to curethe cross-linking agent, thereby cross-linking the yarn and setting thebulked configuration; d. passing said cross-linked yarn through acatalyst solution to partially break the cross-links while applying afalsetwist to the wet yarn; and e. then heating the wet, falsetwistedyarn to recure the cross-linking agent to set the falsetwist, therebyproducing a cross-linked stretchable bulked yarn.
 3. Apparatus forimparting a stretchable, bulked configuration to cellulosic and othertextile yarns comprising: a. a source of supply of said yarn; b. a tankfor containing a solution of chemical cross-linking agent to react withthe yarn, said tank having a yarn inlet point and a yarn exit point; c.transducer means mounted within said tank; d. means for generating anelectrical signal having at least a sonic frequency connected to saidtransducer; e. heating means disposed outside and beyond the yarn exitpoint of the tank; f. transporting means for passing yarn from thesource of supply in proximity to the transducer and then through theheating means, said transporting means including first guide means forguiding yarn from said source of supply to the entrance point of thetank, second guide means to maintain yarn immersed in the tank inproximity to the transducer, first driven means for withdrawing yarnthrough the exit point of the tank while applying a minimum of tensionto the yearn, and second driven means beyond the heating means fordrawing yarn from the first driven means through said heating means; andg. means disposed betweeN said first and second driven means forapplying a falsetwist to the yarn prior to its passage into the heatingmeans.
 4. Apparatus for imparting a stretchable, bulked configuration tocellulosic and other textile yarns comprising: a. a source of supply ofsaid yarn; b. a first tank for containing a solution of a chemicalcross-linking agent to react with the yarn; c. transducer means mountedwithin said first tank; d. means for generating an electrical signalhaving at least a sonic frequency connected to said transducer; e. asecond tank for containing a cross-link breaking catalyst solution; f.first heating means located between said first and second tanks; g.driven windup means for winding up finished, treated yarn; h. yarntransporting means for passing yarn, serially, from the source of supplythrough the first tank, the first heating means, through the secondtank, and finally to said windup means, said transporting meansincluding means for guiding yarn into and out of said first tank whilepassing said yarn in proximity to the transducer, means for guiding saidyarn from the first tank through the first heating means to the secondtank, and means for guiding said yarn from said second tank to the yarnwindup means; i. means for driving said windup means while applying aminimum of tension to the yarn; j. second heating means disposed betweenthe second tank and windup means for heating yarn withdrawn from saidsecond tank; and k. means disposed between the windup means and thesecond tank for applying a falsetwist to the yarn prior to its passagethrough the second heating means.